Development of Intergeneric and Intrageneric Somatic Cell Nuclear Transfer (SCNT) Cat Embryos and the Determination of Telomere Length in Cloned Offspring

Abstract

Somatic cell nuclear transfer (SCNT) holds potential as a useful tool for agricultural and biomedical applications. In vitro development of marbled cat intergeneric SCNT reconstructed into domestic cat cytoplast revealed that cloned, marbled cat embryo development was blocked at the morula stage. No pregnancies resulted from the transfer of one- to eight-cell stage embryos into domestic cat surrogate mothers. This suggested that abnormalities occurred in the cloned marbled cat embryos, which may be associated with incomplete reprogramming during early embryo development. Two pregnancies were established in surrogate mothers that received cloned domestic cat embryos, but SCNT offspring developed abnormally. Some specific phenotypes that were observed included incomplete abdominal wall disclosure, improper fetal development. In addition, some of the fetuses were mummified or stillbirths. The two live births died within 5 days. Telomere lengths of cloned kittens as determined by qualtitative polymerase chain reaction (qPCR) were inconclusive: some were found to be shorter, longer, or the same as donor control cells. Our findings support the hypothesis that telomere lengths do not govern the health of these cloned animals. A lack of complete reprogramming may lead to developmental failure and the abnormalities observed in cloned offspring.

Cheetah interspecific SCNT followed by embryo aggregation improves in vitro development but not pluripotent gene expression

“…We obtained similar or higher morula formation in Dc cloned embryos compared to other reports (Gó mez et al 2003, Thongphakdee et al 2006, Imsoonthornruksa et al 2012. Despite this fact, only 40-50% of cleaved embryos were able to reach this stage.…”

“…The successful application of iSCNT in felids was demonstrated by the birth of African wild cats (Felis silvestris lybica) (Gó mez et al 2004b) and sand cats (Felis margarita) (Gó mez et al 2008), as well as by pregnancies reported from embryos generated by the fusion of leopard cat (Prionailurus bengalensis) cells with Dc enucleated oocytes (Yin et al 2006). Despite these achievements, pregnancies and births after iSCNT are still elusive, as shown in several reports (Thongphakdee et al 2010, Gó mez et al 2011, Imsoonthornruksa et al 2012.…”

Effects of donor cells’ sex on nuclear transfer efficiency and telomere lengths of cloned goats

“…Cloned sheep or goats often had shorter telomere length than their age‐matched controls (Shiels et al., ; Betts et al., ; Alexander et al., ), and this is also in agreement with our study. However, cloned cattle differed significantly and exhibited longer, shorter or the same telomere length compared to age‐matched counterparts (Tian et al., ; Lanza et al., ; Miyashita et al., ; Konishi et al., ), and cloned cat resembled cattle (Imsoonthornruksa, Sangmalee, Srirattana, Parnpai, & Ketudat‐Cairns, ). Cloned pigs often had the same telomere length as their controls (Jiang et al., ; Kurome et al., ), and it was also shorter than donor cells (Xie et al., ).…”

Tiger, Bengal and Domestic Cat Embryos Produced by Homospecific and Interspecific Zona‐Free Nuclear Transfer

“…Specifically on felids, the successful application of iSCNT was confirmed after birth of African wild cats (Felis silvestris lybica; G omez et al 2004) and sand cats (Felis margarita;G omez et al 2008), and pregnancies obtained in leopard cats (Prionailurus bengalensis, Yin et al 2006). Despite these achievements, it is still very difficult to obtain pregnancies and births after iSCNT, as was shown in several reports (Thongphakdee et al 2010;G omez et al 2011;Imsoonthornruksa et al 2012). The causes of its inefficiency are many, and they could be related to failures in nuclear-cytoplasmic communications (St John et al 2004) and to the basis of nuclear transfer itself (Niemann et al 2008;Palmieri et al 2008).…”

“…; Imsoonthornruksa et al. ). The causes of its inefficiency are many, and they could be related to failures in nuclear‐cytoplasmic communications (St John et al.…”